The major insurance coverage provisions of the Affordable Care Act go into effect in January 2014, providing new insurance options for people without health insurance and insurance market protections for consumers. The Commonwealth Fund Biennial Health Insurance Survey of 2012 finds that the reform law has significantly increased health insurance coverage of young adults. But the findings also underscore why it is critical that implementation continue on schedule. Nearly half (46%) of adults ages 19 to 64, or an estimated 84 million people, did not have insurance for the full year or were underinsured and unprotected from high out-of-pocket costs. Two of five (41%) adults, or 75 million people, reported they had problems paying their medical bills or were paying off medical debt. And more than two of five (43%), or 80 million people, reported cost-related problems getting needed health care.